Why and Wherefore of Increased Scientific Collaboration

We appreciate assistance with the survey from John Trumpbour and input from Jennifer Amadeo-Holl, Paula Stephan and Andrew Wang. We received helpful comments from Adam Jaffe, Ben Jones, Manuel Trajtenberg and participants at the NBER "The Changing Frontier: Rethinking Science and Innovation Policy" Conferences. This research was supported in part by the National Science Foundation's National Nanotechnology Initiative, Award 0531146. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.